1. Field of the Invention
The invention relates to a transport and storage container for liquids, comprising a pallet-like underframe which is designed for handling by means of a stacker truck, shelf servicing device or like transport means, comprising a parallelepipedal or cubicle inner container of plastic with a closeable fill and outlet opening or a closeable fill and removal opening, and a metal cage resting against the inner container and comprised of crossing horizontal and vertical cage rods of metal.
The invention also relates to a method for manufacturing the inner container of the transport and storage container described above.
2. Description of the Related Art
From German patent DE 197 22 194 C2 transport and storage containers of the aforementioned kind are known which have a blow-molded inner container of plastic material and are used for storing and for transporting liquid goods of all kinds in the chemical, pharmaceutical, petroleum, and foodstuff industries.
The stringent environmental laws and regulations require the transition from single use containers such as pallet containers and barrels for the transport and storage of liquids of different kinds to multi-use containers, the conversion to containers of greater volume with the goal of reducing the residual amounts, and the development of new multi-use containers which, with respect to relief of the environment with regard to harmful substances, can be reconditioned and whose plastic components contaminated by the transported and stored liquid goods can be disposed of in an optimal way by a contaminant-reduced or even contaminant-free disposal method, for example, by combustion.
It is an object of the present invention to further develop the transport and storage container of the aforementioned kind with respect to economical reconditioning and an inexpensive manufacture as well as an optimal disposal of the plastic inner container.
In accordance with the present invention, this is achieved in regard to the transport and storage container in that the flexible inner container is comprised of an inner envelope of a plastic foil and an outer envelope of a woven material, in that the inner container is fastened to the upper frame of the cage and/or a protective cover (cover rods) of the transport container, and in that the inner envelope is positioned in the outer envelope of the inner container.
In accordance with the present invention, this is furthermore achieved in regard to the method of manufacture by the steps of:
1. Cutting the tailored mantle piece for the outer envelope of the inner container from a woven web on a cutting table and transferring the axis markings and edge markings for the parallelepipedal or cubic mantle of the outer envelope to be produced by sewing from the cutting table onto the tailored mantle piece for proper positioning of the mantle, the tailored bottom piece, and the tailored cover piece of the outer envelope for a later sewing or gluing to the inner envelope;
2. Sewing the abutting edges of the tailored mantle piece on the left-hand side of the woven material to form the mantle of the outer envelope;
3. Cutting a tailored cover piece from a woven web for the outer envelope of the inner container with rounded corners and an opening for insertion of the fill socket of the inner container on a cutting table and transferring the axis markings from the cutting table onto the tailored cover piece;
4. Sewing securing straps at predetermined locations onto the tailored cover piece;
5. Cutting a tailored bottom piece from a woven web for the outer envelope of the inner container with rounded corners on a cutting table and transferring the axis markings from the cutting table onto the tailored bottom piece;
6. Cutting a tailored piece for the inner envelope of the inner container of a hose of foil material having lateral folds folded to the longitudinal center axis on a cutting table, wherein the longitudinal edges of the tailored piece have approximately twice the length of the length of the inner container to be manufactured and the transverse edges of the tailored piece are greater by a certain amount than the width of the inner container;
7. Cutting the openings for insertion of the fill socket and the outlet socket out of the upper and the lower foil web, respectively, of the tailored piece of the inner envelope;
8. Contour welding of the inner envelope of the inner container, wherein, for a tailored piece of a hose of a single layer foil material having lateral folds, in a first welding cycle the stacked and aligned transverse edges with the intermediately positioned edges of the folds of the folded tailored piece are welded; longitudinal edge strips are formed at the longitudinal edges of the upper foil web of the tailored piece by welding the upper foil web and the upper portion of the corresponding fold positioned underneath by means of a longitudinal welding seam, which longitudinal edge strips extend symmetrically to the center of the two longitudinal edges of the tailored piece; and, from the two ends of the longitudinal welding seams, receptively, slanted welding seams are placed that extend through the upper foil web and the upper portion positioned underneath of the corresponding fold to the center of the transverse edges of the tailored piece for separating off corresponding portions of the upper foil web and the folds of the tailored piece; and wherein in a second welding cycle the same contour welding of the lower foil web of the tailored piece and the lower portions of the folds adjoining the lower foil web is performed for forming lower longitudinal edge strips, with the exception of the welding of the transverse edges of the tailored piece already carried out in the first welding cycle;
9. Contour welding of the inner envelope of the inner container, whose tailored piece is comprised of a multi-layer foil, in particular, a two-layer foil of a weldable foil material, such as polyethylene, and a non-weldable foil material, such as polyamide, in a welding cycle according to method step 8;
10. Attaching by welding a tailored piece of foil material, having two edges formed as fastening loops and a fill socket attached by welding, onto the upper foil web of the contour-welded tailored piece of the inner envelope of the inner container, wherein the fill socket is welded to the edge area of the fill opening;
11. Attaching by welding the outlet socket with the edge area of the outlet opening in the lower foil web of the contour-welded tailored piece of the inner envelope of the inner container;
12. Folding the contour-welded inner envelope of the inner container onto the container footprint dimensions, wherein the welded longitudinal edge strips are positioned flush with one another;
13. Left-hand sided sewing or gluing of the welded upper longitudinal edge strips of the folded inner envelope to the tailored cover piece of the outer envelope;
14. Left-hand sided sewing or gluing of the welded longitudinal edge strips of the folded inner envelope to the tailored bottom piece of the outer envelope;
15. Unfolding the inner envelope and sewing or gluing the tailored mantle piece of the outer envelope about the periphery to the tailored bottom piece of the outer envelope and the lower longitudinal edge strips of the inner envelope as well as to the tailored cover piece of the outer envelope and the upper longitudinal edge portions of the inner envelope.
The transport and storage container for liquids according to the invention and the method for manufacturing the plastic inner container of the transport container have the following advantages.
The configuration of the inner container as a flexible container, which is comprised of an inner envelope of plastic foil and an outer envelope of a woven material, makes it possible, in comparison to liquid containers with an inner container blow-molded of plastic material, to reduce the tare weight and the transport costs due to the reduced thickness of the foil and woven material and a considerable reduction of the plastic material which is contaminated by paints, lacquers, and similarly environmentally harmful liquids so that the disposal of this plastic material is not problematic. The transport container can be reconditioned by a simple exchange of the inexpensive inner container at the manufacturing and filling facilities for liquid goods in an inexpensive way wherein the minimal space requirement of the flexible inner container as a result of its foldability and the lower manufacturing costs of the inner container provide inexpensive stock holding. Finally, the manufacture of the flexible inner container of a plastic foil and a woven material, preferably of plastic material, is more cost-efficient than the manufacture of the blow-molded plastic inner container in expensive blow-molding machines which require high investments.